ncreed@ndsuvax.UUCP (Walter Reed) (11/24/87)
I need to know how to set up the serial device to generate a signal when
the carrier drops. I am writting the serail routines for my BBS and
don't want to have to do a CheckCarrier() type of thing all over the place.
Yes, I know about the CMD_QUERY, but that's not what I want. If I did that,
I could set up a timer_request to check the carrier once a second, but I
would rather have it tell me when the carrier drops. At least, it would be
nice if I could have a flag like SERB_CHECKCD that would enable checking of
the carrier and return an error of SerErr_NOCD if the carrier is lost.
Please CBM, PLEASE release the source for the serial device, and / or add
this capability... It would make writting an AUX: device easier, a BBS
easier... This is such a small change, and I request that you put it into
version 1.3. We need it. Gee, it would be nice to detect a SIG_HUP and
deal with it.
--
Walter Reed UUCP : uunet!ndsuvax!ncreed
Internet : ncreed%NDSUVAX.BITNET@WISCVM.WISC.EDU
Ph 701-235-0774 Bitnet : ncreed@ndsuvax OR NU105451@NDSUVM1
-------------------lyles@tybalt.caltech.edu (Lyle Scheer) (11/24/87)
In article <498@ndsuvax.UUCP> ncreed@ndsuvax.UUCP (Walter Reed) writes: > >I need to know how to set up the serial device to generate a signal when >the carrier drops. I am writting the serail routines for my BBS and >don't want to have to do a CheckCarrier() type of thing all over the place. >Yes, I know about the CMD_QUERY, but that's not what I want. If I did that, >I could set up a timer_request to check the carrier once a second, but I >would rather have it tell me when the carrier drops. At least, it would be >nice if I could have a flag like SERB_CHECKCD that would enable checking of >the carrier and return an error of SerErr_NOCD if the carrier is lost. > >Please CBM, PLEASE release the source for the serial device, and / or add >this capability... It would make writting an AUX: device easier, a BBS >easier... This is such a small change, and I request that you put it into >version 1.3. We need it. Gee, it would be nice to detect a SIG_HUP and >deal with it. > That's odd. I've had a BBS program written for the Amiga since about a year and a half ago. The way I do it is, after I output a line of text to the serial port and CON: device in my window, I check for CD with CmdQuery. It doesn't slow it down much. I also check during my input routine, with no real loss of input speed. In fact, I'm quite impressed with how well the Amiga does with this sort of thing. I now have my BBS program doing mostly wait(), so its ready for me to start figuring out how to make it re-entrant, so that I can multitask more than one serial port(ASDG or someone, I NEED MORE SERIAL PORTS!) Wonko the Sane (you call this SANE??) Disclaimer: I am totally irresponsible. So shoot me then.
dillon@CORY.BERKELEY.EDU.UUCP (11/25/87)
>I need to know how to set up the serial device to generate a signal when >the carrier drops. I am writting the serail routines for my BBS and >don't want to have to do a CheckCarrier() type of thing all over the place. >Yes, I know about the SDCMD_QUERY, but that's not what I want. If I did that, >I could set up a timer_request to check the carrier once a second, but I >would rather have it tell me when the carrier drops. At least, it would be >nice if I could have a flag like SERB_CHECKCD that would enable checking of >the carrier and return an error of SerErr_NOCD if the carrier is lost. I just do this before sending a CMD_READ... since you want to do a SDCMD_QUERY anyway to get the number of bytes in the read buffer (You NEVER read one character at a time if you can help it). You need some sort of timeout on the CMD_READ anyway or your BBS can hang even with an active carrier (e.g. xmodem transfer dies, user doesn't do anything for 10 minutes..) I agree, there should be a way for the serial.device to signal you. Still, most modems send a 'NO CARRIER' message when the carrier drops and you would catch it then. But if you *still* want to do this, you would have to create a separate task which periodically sends SDCMD_QUERY requests to the serial.device and sets some global variable. But I say you can do it within your read/write routines just as easily. SPEED CONSIDERATIONS: As long as you read as many chars that are available (in one CMD_READ), and write as many chars as you can (in one CMD_WRITE), you can easily do a SDCMD_QUERY in between without slowing the program down. Remember that syncronous IO calls such as SDCMD_QUERY are extremely fast. Additionaly, it should be noted that by using asyncronous CMD_WRITE's a SDCMD_QUERY done after the CMD_WRITE is issued (using a different iorequest of course) would be completely absorbed by the write-time. -Matt